* config/i386/linux64.h: New spec file for Linux x86-64 support.
* config.gcc: Fix tm_file settings for x86-64.
* config/i386/x86-64.h: New file with OS independent x86-64
definitions.
* config/i386/biarch64.h: New file used to configure compiler
to biarch/64bit compilation.
* config/i386/i386.c: (override_options): Set flags default
for 64bit compilation.
* i386.c (legitimize_pic_address): Add missing bits of 64bit support.
(ix86_expand_int_movcc): Optimize DImode conditional moves with
constants on x86_64.
(ix86_attr_length_immediate_default): Support MODE_DI.
* i386.md (fixdi splitter): Add missing "&& 1" in splitter
condition.
(indirect_jump, tablejump): Turn into expander.